Background: The differences between using sirolimus-eluting stents (SESs) and paclitaxel-eluting stents (PESs) in the vascular response at 9 months after implantation were examined with optical coherence tomography (OCT).
Methods and results: OCT was carried out in 33 SESs [33 patients, 19 with acute coronary syndrome (ACS) and 14 with stable angina pectoris (SAP)] and 27 PESs (27 patients, 15 with ACS and 12 with SAP) at 9 months after stent implantation. Stent strut coverage and apposition at each strut were evaluated. The frequency of uncovered struts was significantly higher in SES (12.5+/-15.2 vs 4.9+/-7.9 %, P=0.01). The incidence of complete covered stents with neointima was 9.1% (3/33) in SES and 29.6% (8/27) in PES (P=0.05). The pattern of neointima in PES was more heterogeneous than that in SES (1.3+/-0.5 for SES vs 2.0+/-0.6 for PES, P<0.001). The intracoronary thrombus was frequently detected in SES [10 (30.3%) in SES vs 5 (18.5%) in PES, P=0.29].
Conclusions: Uncovered struts were frequently observed in SES, but the pattern of neointima was more heterogeneous in PES at 9 months. In addition, stent coverage was incomplete in both stent groups at 9 months after stent implantation.